October 14, 2013:
The Sell in April or May then Buy back in October or November based on
MACD and the Seasonal Timing Strategy (STS) made popular by Sy Harding
is about to turn favorable for a market buy. From "Sy Harding Seasonal Timing Strategy,"

Sy Harding applies the
Moving Average Convergence Divergence indicator, or MACD, to the DJIA
(Dow) after the average best time to leave the market, April 20,
following the "sell in May and Go away" strategy. Likewise, around
the best days on average to enter the market, October 16, Harding's STS
looks for positive MACD to enter the market again.

For example. Sy
waits for the MACD to turn positive after October 16, the average best
day to enter the stock market based on the "Seasons in the Sun
Strategy." Harding writes:

The idea is that if a
rally is underway when the October 16 calendar date for seasonal entry
arrives, as indicated by the MACD indicator, we will enter at that time.
However, if the MACD indicator is on a sell signal when the October 16
calendar date arrives, indicating a market decline is underway, it would
not make sense to enter before that decline ends, even though the best
average calendar entry date has arrived. Instead, our Seasonal Timing
Strategy simply waits to enter until MACD gives its next buy signal,
indicating that the decline has ended.

My chart below shows the MACD for the S&P500 as of today. You can get a live version of this 6-month chart at